Surviving the Ice: A critical review of cold tolerance strategies in Antarctic nematodes

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Thesis Discipline

Science

Degree Grantor

University of Canterbury

Degree Level

Postgraduate Certificate

Degree Name

Postgraduate Certificate in Antarctic Studies

Antarctica presents an extreme environment. Diversity is restricted yet life thrives,
particularly nematodes. Nematodes are a dominant soil invertebrate in Antarctic ecosystems
and have developed a suite of cold tolerance mechanisms to cope with freezing events and
desiccation. Panagrolaimus davidi is one of these nematode species, believed to have
exceptional cold tolerance abilities, above and beyond that of its counterparts. Several years
of research has produced an impressive literature base on cold tolerance mechanisms. Upon
reading this literature it is immediately clear that investigators agree to the classes of cold
tolerance mechanisms and the species which employ each strategy. However, there are areas
requiring further research; switching between strategies is apparent in some species, which is
suggestive of plasticity among mechanisms, yet a solid conclusion has not been reached. In
the case of P. davidi there is little information as to how members of Panagrolaimus vary in
their cold tolerance mechanisms. It is also obvious that studying cold tolerance abilities can
be problematic as nematodes have to be removed from their natural habitat.